ARPA-E recently held an event in its public workshop series - "High Density Thermal Energy Storage," on January 31, 2011 in Arlington, VA. Thermal energy transport and conversion play a very significant role in more than 90% of energy technologies. Approximately two thirds of thermal energy is wasted. Thermal energy storage can significantly reduce this waste and enhance the efficiency of energy delivery and consumption.  

The primary objectives of the workshop were to:

• Identify challenging technical barriers for thermo-chemical and physical (phase change & sensible heating) energy storage.
• Identify ways to significantly increase entropy change density (per unit mass and per unit volume) for a given temperature range to increase enthalpy change density.
• Cost effective high density (per unit mass and per unit volume) thermal energy storage for applications ranging from low temperature (~ 0 oC) to high (~1000 oC).
• High and low temperature thermal insulation for thermal energy storage for sensible and phase change based systems.
• Explore possibilities of insulation-free thermal energy storage.
• High pressure storage systems.
• Ability to tune the thermal energy storage system delivery temperature using catalysis and other methods.

View the workshop agenda (pdf). Proceedings from the meeting are summarized below.

Speakers and Presentations:

1. Welcome (pdf) - Arun Majumdar, ARPA-E Director 2. Thermochemical Energy Storage: Possibility of Chemical Heat Pump Technologies (pdf) - Yukitaka Kato, Tokyo Institute of Technology 3. Concentrating Solar Thermal Energy Storage (pdf) - Anoop Mathur, Terrafore 4. Thermal Energy Storage Systems for Peak Electricity from Nuclear Energy: Gigawatt-day to Gigawatt-year (pdf) - Charles Forsberg, Massachusetts Institute of Technology   Breakout Sessions:   1. ThermoPhysical Storage –  Nicholas Cizek and Ilan Gur, ARPA-E Report (pdf) Questions (pdf)   2. ThermoChemical Storage – Karma Sawyer and Eric Toone, ARPA-E Report (pdf) Questions (pdf)   3. Thermal Storage for Nuclear Energy – Harold McFarlane, Idaho National Laboratory Report (pdf) Questions (pdf)   4. Low Temperature Systems – Nicholas Cizek and David Shum, ARPA-E Report (pdf) Questions (pdf)   5. High Temperature Systems – Ashok Gidwani and Karma Sawyer, ARPA-E Report (pdf) Questions (pdf)   6. Alternate Applications for Thermal Storage – Ilan Gur, ARPA-E Report (pdf) Questions (pdf)